mdb_pwalk()

Initiate
a local walk starting at addr using the walker
specified by name, and invoke the callback function func at each step. If addr is NULL,
a global walk is performed (that is, the mdb_pwalk() invocation
is equivalent to the identical call to mdb_walk() without
the trailing addr parameter). This function returns
0 for success, or -1 for error. The mdb_pwalk() function
fails if the walker itself returns a fatal error, or if the specified walker
name is not known to the debugger. The walker name may be scoped using the
backquote (`) operator if there are naming conflicts. The data parameter is an opaque argument that has meaning only to
the caller; it is passed back to func at each step
of the walk.